The Syrian city of Qusayr lies just 10 miles over the border from Aarsal in northern Lebanon. But the Syrians now crowding into Aarsal said the trip to get here from Qusayr required walking for days.

Those who fled said that as many as 40,000 people remain in Qusayr, a city that has been a stronghold of the rebels fighting the Syrian government for more than a year. But government troops, bolstered by recently trained militias, now surround the city, in apparent preparation for storming it. The checkpoints they’ve set up on the roads around it make fleeing the besieged city dangerous – and complicated.

“To leave Qusayr is to risk death,” said one man who had made the journey along a circuitous route intended to avoid Syrian army checkpoints. The man, who refused to give his name because he feared reprisals from the Syrian government, said the trip took 10 days, most of it on foot.

To stay in Qusayr is to risk death as well. Government troops’ overrunning of rebel-held districts has led to some of the highest civilian death tolls of Syria’s civil war. Last summer, when Syrian troops moved into Daraya, outside Dasmascus, hundreds of civilians reportedly were killed.

Qusayr’s population, normally about 35,000, had dropped to about half as residents fled the fighting that ended in a rebel victory in July 2012. Now the population has swelled again as thousands fled to the city in recent weeks after government troops seized nearby villages from rebel forces.

The Syrian government dropped leaflets last week on Qusayr and villages nearby, urging residents to leave the area to avoid bloodshed and promising rebel fighters safety if they surrender.

The likelihood of a rebel surrender seems small, however. People who’ve fled Qusayr in recent days said that thousands of rebel fighters have dug in and are preparing to make a stand, even though their supply of ammunition was running low.

After a string of quick victories earlier in the month, the government’s forces have had more difficulty dislodging rebels from some of the towns and villages outside Qusayr that the rebels have occupied for months. At least one, called Abel, northeast of Qusayr, switched hands twice in the last week, a dynamic that has marked much of the last year of Syria’s civil war, particularly in the area along Syria’s main north-south highway, where the frontlines have changed little even as casualties have increased.

The likely fight for Qusayr is part of what appears to be a government strategy to carve out a safe zone between the Mediterranean and the Orontes River to which its sympathizers could retreat, if necessary, from the nation’s capital, Damascus. Qusayr is on the main road that links Damascus to the coastal area.

Qusayr also is critical to rebel strategy. When government troops last year drove rebels from the Baba Amr neighborhood of Homs, Syria’s third largest city, many rebels fled to Qusayr, which lies near key routes along which the rebels smuggle in weapons from Lebanon and smuggle their wounded out. The weapons smuggled in help rebels continue to fight in parts of Homs.

The success of the government’s offensive has fostered a new sense of cooperation among the rebels, who have never been organized as a large fighting force. But coordination is growing. On the eastern side of Damascus, rebel battalions that had been fighting each other one month ago are now cooperating in a battle to reopen a rebel supply route all of them use. It remains to be seen, however, if such coordination will outlast the battle, which so far has been unsuccessful in dislodging the government’s forces.

The continued fighting has only exacerbated the country’s refugee crisis, and refugees arriving in Lebanon on Thursday seemed unsure of where they would go as they were met with tales of homeless families. Some were waiting for the construction of a camp to be completed in Aarsal.

“We have nowhere to go,” said one woman, sobbing as she beseeched the municipal authorities in Aarsal for help. They in turn complained that the local community had run out of resources to aid the refugees, approximately 24,000 of whom now call Aarsal home, likely doubling the city’s population.

On Tuesday, the Syrian Observatory for Human Rights, a group that tracks casualties in Syria, raised its total estimate of dead to more than 94,000 since the beginning of the rebellion in March 2011. The new figure included thousands of government troops and supporters who had not been accounted for in previous death tolls.